Portable electronic computer



y 30, 1961 A. G. THoMAs 2,986,333

PORTABLE ELEcTRoNc cOMPUTER Fi1ed June 8, 1955 8 sheets-Sheet 2 F11edJune 8, 1955 A. G. TH0MAs PORTABLE ELEcTRONc coMPUTER 8 sheetSSheet 3ZNyEToR.

y 1 A. G. THoMAs 2,986,333

PORTABLE ELEcTR0Nc cOMPUTER Filed June 8. 1955 8 SheetsSheet 4 May 30,1961 A. G. THoMAs PORTABLB ELcTRoNc c()MPUTER Fi1ed June 8 1955 8sheetsSheet 5 May 30, 1961 A. G. THoMAs PORTABLE ELEcTR0Nc coMPUTER 8SheetSSheet 6 F ed June 8 1955 INVENTOR A. G. THoMAs 2,986,333

May 30, 1961 PORTABLB ELEcTRONIc coMPUTBR F11ed June 8 1955 Ma 30, 1961A. G. THoMAs PORTABLE= ELEcTRoNc coMPUTBR 8 Sheetssheet 8 F11ed June 81955 Un S t s P c o foRTALE ELECTRoNIc CoMUTER A1beff T,honlaS,(:11affonoogo, Tenn. (133 Bomngwood Road, Chof1offeSv111e, va,)

Eed June 8, 1955, ser. No. 313,973

55 c18imS. (CL 235150) T11is invention relates to calculating Inachinesof con1- puterS and iS pafticularly directed to an e1ectTonic calculaforfor quickly peffofIning IT1111tiplicatio11, diviSion, addifion, andSubffaction.

111 pfior calcU1atofs of electfonic fype thefe haS been Innchcon1p1ication and a nun1ber of units of elabofate and eX ensiveconStfuction have been included. It iS therefofe an obiect of thepTesent invention fo pfovide a relatively Sifflple calculating devicevhich iS feliable in operation and vvhich can be So1d at n1odefafe cost.

Anothef obiect iS to provide a calculating lIlachine Which is eaSy toopefate and Which fuTniSheS desifed ansvve1S q11ick1y.

A fufthef obiect iS to pfovido a caloulator of co1npufer in vv11ichdivision iS to a 1afge extent anfon1atic.

- /n additional object is to pfovide a conputef in vhich the number tobe divided and the divisof can be fead11y Set in the n1achine.

A Still fufthef obiect iS 1he provision of a caloulator Which can bequickly Set foI' In111t1plication or for division.

Anothef obiect iS the pTovision of an electfonic co1cn1a-Z toI Which iSTeadily Settable fof pefforIning fnI1ltip1ica tion, division, addition,of subfTaction.

A fufther objecf iS to pfovide a c1c1ator in vh1ch numera1s indicating anumbef are in a1ignInent.

An addifional objeot iS to provide a Suitab1e electfonic counting tubefor a ca1culatof.

()thef obiectS Wi11 be evident in the following oesorip tion. v

In the dfawingS: l

FiguTe 1 iS a top plan vievv of an electronic ca1cu1ator shoving thecover paft1y bfoken avvay to fovea1 e1ectTical circuitS and coInponenfS,

Figure 2 1S a ffagmentaTy plan view of a numefa1 sheet Which is SHdab1ymounted fof bfinging either of 1Wo setS of nUInera1S into fegiSfe1 WithWindows in the covef.

Figure 3 is a ffagInentafy cifcuit diagraJT1 Shovving transfofnefS foI)11ISing fhyfatfon cifcI1its instead of Tesistofs.

Figure 4 iS an e1evafion, as Seen ffoIT1 tho light, of one of theIn111tip1icand key Units of Figure 1.

Figure 4Z) iS an enlafgen1ent of fhe 1ovver left poftion of Figufe 1.

Figufe 46 is an enlaTgenlent of the 1eft centef portion of Figufe 1,including the electro-n1echanica1 SWitch. v

Fignfe 4(f is an enlafgen1enf of the uppef counting cir cuit poftion ofFigure 1.

Figufe 48 iS an enlargeInent of the 1ovvef fight porf1on of Figufe 1 andincluding Sonle connectionS 1eading to Figufe 4.

Figufe 5 iS a part Sectiona1 e1evation aS Seen fron1 the front, of thekey IInit of Fignfe 4o.

Figufe 6 is a fTagInenfafy plan view of a type of con stTUction of thecontacts in the Unit of Figufe 4o.

Figufe 7 is a ffagInenfaTy plan vievv ShoWing an a1tof nafiveconstfuction fof contacfS of tho nnit ShoWn in Figufe 4o.

Figure 8 iS a ffagnlentary vieW Showing the SWifch armS of Figufe 1 in aposition for stafting the pfocess^ of division.

Ffgufe 9 is a fragTnentafy cifcuit diagram Showing a F. TeSe WindovvSInay con1pfise ho1es in the cover or they Inay be n1ade of cleaT plaSticof the like. Beneath cover Z and cloSe1y adacent thefeto iS tfanSpafentslidable plate of sheet 3 Which is Inounted on tfack 4 and on a siInilarffack on the oppoSite Side of the caSing so that the Sheef n1ay ben1oved back and fofth ove1 a short distance in direction parallel vviththe fows of WindovvS, So1enoid 5 iS faStened to the ffame of thefnachine and itS afnat11Te 5 iS faStened to sheet 3. (:on1- pTeSSionSpring 7, Surfounding plunger 6, noflTla11y holds the sheef in itsreafwafd position with nun1era1S ffom 0 o 9 pfinted on fhe sheet infegister With the WindoWS of each Tow as indica1ed by the heavynUn1era1s of Fig ufe 2. These nun1efals ordinafily are not InaTked1yvisible but are qnite viSible vvhen inu1inated ffon1 beneath byfeSpective 1amps 8 Which may be of filament type but gaSeous 1aInpScould be uSed dvith pToper circ11it coIn ponenfs. It is poSSible a1So toplace thyratTonS 9 beneath the Windows so that the light ffom thethyratronS Wi11 il111f1inate the nUInefals, When fhe 1hyfatfonS arefiI'ed.

Sheet 3 n1ay be fnade of ffansparent or ffanSlucent plaStic of maycompfiSe p1asfic in a Inetal ffame. Fnf thermofe the Sheet may be ofmetal with ho1es Hed of covefed vvith tfanSpaTent plaSfic havingnuInefalS pfinfed thereon; of the holeS in the Inetal n1ay be punchedout in ShapeS of numefalS So that the nnn1erals will appear aSiHun1inated Windows above laIn S Which n1ay be sUp p1ied current. Sheet3 1ay be placed s11ff1cienfly beloW coVe1 2 that the nu1era1S afe notveTy viSible un1esS a laInp beneath is il1I1n1inated, of the holes incover Z n1ay be coveTed vvit11 gfound g1aSS of tfanslUcent plastic sothe nun1era1S aTe not viSb1e at a11 until iHunlination froIn the lan1pssffikes the tTanSlucent covefing,

The Sheet 3 has a1So anothef Set of 111lnlefa1S fof each fow, fon1 0 to9 Tunning in opposite direction and in line With the numeTals shown. 1hese numera1S are placed betvveen the ones indicated and are in feveTSedordef as Shown in ffagmentaTy FigUfe Z The heavief nun1eTals Teadingffon1 0 to 9 afe fof I1111tiplaction and addifion, and the fine 1inen1In1efals Teading ffon1 0 to 9 in oppoSite difection are fof diviSi()1and subtraction. ()ne teffI1inal of solenoid 5 iS connected vithnegative 1ne 10 of a fecfi1ieT, baftery dynan1o, of other Suitablesoufce of direct c11Trent 3Z, and the othef tefInina1 of thiS Solen()idis connected With teTIninal G Which is connected to a tefIninal ofSWitch 11 the othef teffninal of vVhich is connected to p()Sitive 1ine12 of the difect cur fenf Source 32. vvhen, thefefofe, Svitch 11 iscloSed, for diviSion, Solenoid s iS energized and plunger 5 is punedinto fhe Solenoid fof its full traveL thereby bfing ing the f1fle 1inenumefalS fof diviSion into regiStef With the WindovvS in covef Z, 111connection Wifh Fig11fe 1 it Should be Ten1enlbefed that the nuInera1sShoWn in IOWS A, B, C, D, E, F afe fof division.

There aTe ten thyTatfonS 9 fo1 each Tov of laITlpS 8. T he lanlps of fowA afe connected betvveen poSitive bus ba1 13 and the fespective anodesof the thyTafronS tho Pafonfeo May 30, 1951 n1if1al oonnected to thegfid of the tube.

78.,'78 ,and 78 afe elecffica1Iy coonocfed by Wifo 10,, so that each ofthese Switch elefflentS iS connected to hegative Hne 10 and 10 tonegative Hne 96. SWitch offfS 77 and 78 afe connected With tfanSfoffffefSec bndafy 88 thfOUgh confacts 81 vvinding 88 iS associated Withpfifflafy vvinding 89. The contact butfons afe faStened to a. Suitab1einSUlating plate Which Tnay be paft of the ffaIfle of attached fhefeto.T11e paif of con tactS 79 afe connected to seoondafy Winding 82,, vvhichfS aSSociated With ffanSfofnlef pfiInafy 1vinding 82 Which is in SefiesWith the Zefo lamp 8 aS indicated fof fflultip1ication. The othefteffniffal of pfifnafy Wiflding 82 iS connected ith t11e zefo thyfatfon9 conSidefing that the nflfnefalS in the windows afe Set fof fnu1tiplication. si1i1afly, the paif of contactS 80 afe con nected With theteffninals of Secondafy Winding 82 aS Sociated vvith tfanSfoffnefpfifnafy vvinding 83 vvhich is connected in sefieS vvith the zefo lafnpand associated thyfatfon in the E fow in the Safne fnannef aS descfibedfof vvinding 82 The paif of contact buttonS 81 afe Sin1ilafly connectodvvith tfanSfofmef Secondafy fvindiffg 84 Which is associated vithsifni1afly connected pfimafy winding 85 of fow D.

TfansfofInef pfifnafy Windings 89 and 88, fof fows A and B afe connectedin a sin1ilaf fflannef aS ffansfoffflef pfifnafy vfindings 82 83, and85. Tfansfofn1ef Secondafy WindingS 90, 91, 92, 93 and 94, connected inSefieS With feSpective fesiStofs 20 20 20 20 and 20, afe inductivelyassociated With feSpective pfin1afy Windings 89, 88, 87, 85, and 83. ThefesiStof,Secondafy cofnbinatiof1s 20 -90, 20 91, 20 -92, 20 93 and 20,94afe connected, feSpectively, betWeen buS 1ineS of con ductofs 19 and 14and sifI1ilaf lines fof the othef foWS, including 1iffeS 19 and 14 andlifles 19 and 14 The tfansfofInef pfimafies 82 83, and 85 haveadditiona1 inductive1y aSSooiated Secondafy `Windings 82 82, and 84, aSdescfibed.

T11e SWitch annS of blades 77 and 78 afe connected, fespectively, vviththe poSitive tefn1inal of battefy of othef biaS potential Soufce 95 andnegative line 96, by fneans of eXib1e conductofS 97 and 98. The negativoteffnina1 of biaS Soufce 95 is connected to the gfid of thyfatfon 57,and feSiStof 99 and condenSef 100 afe connected in pafallel betvveen thepoSitive teffnina1 of biaS Soufce 95, and negative lifle 96 to vvhichthe cathode of thyfatfon 57 Inay be connected by nleanS of SWitch 101.

SWifch blade 77 is connected by meanS of flexible conductof 97 to theiunction of battefy 95 and feSistof 99. Sin1ilaf1y, Svvitch blade 78 isconnected to negafive lino 96 by ffleanS of f1exible conductof 98.Svvifoh blade 77 is, by ffleans of f1eXible conducfof 164, connectedWith tefn1inal L /hich is connected to the positive poio of the gfidbias battefy of tllyfatfon 147. The cathode of thyfatfon 102 iSconnected to line 96 and the aS- sociafed anode of tube 102 iS connectedthfough fe siStof 103 to the 1)oSitive tefn1ina1 of difect cuffentpovvef Supply 32 by fneans of conductof 12 QUenchiflg condenSef 104 Sconnected befWeen fhe anodes of tubes 57 and 102 fo canSe the eXtinctionof ono tube when the othef iS flfed. Thyfatfon 102 iS nofn1aHy biaSedflegafively to pfevenf condoction, by biaS battefy of othef potentia1Soufce 105 having ts negafive tef The positive teffnina1 of biaS Soufce105 is connecfed to 9. teffnina1 of Secondafy Winding 106 oftfanSfofnfef T T11o othef feffflinal of Winding 106 iS connocted to 1ine96 vvhich. is connected fo bfush 107 and to the cathode of thyfaffon108. Line 96 iS alSo connected fo the cathode of th} fatfon 109 thfoughfeSistof 110 and to the cathode of electfonic fube 111 thfough fesiSfof112. Thyraffon 109 is flofInally biaSed negatively by biaS Sonfce 113the positive teffninal of vhich iS connecfod to line 96 thfough-feSistof 114. Bfush 115 is connected fo the negative 1offflina1 ofbattefy of othef cuffenf sonfce 116 the poSi 6 tive tefn1ina1 of WhichiS connocted to fhe 1)oSitive tef minal of bias soufce 113 and tooonnected fesiStof 114. BfosheS 107 and do not paSS onffent ffon1 baf!tefy 116 11flti1 contact 41,, on disc 41 bfidgeS thefn. 1n thisspecification the tefn1 battefy vvill be 11Sed to de note a battofy, adifect cuffent onit confpfising fecti fied, filtefed altefnatingcuffent, of any othef Suitable Soufoe of c1ifect cuffent of vo11age suchaS a genefatof.

The anodeS of thyfatfonS 108 and 109 afe connecfod to 1ine 34 thfoughfeSpective feSiStofS 117 and 118, and condenSef 119 is connected tothese anodeS So that one mbe Wil1 be extingniShed if the othef is fifed.Tho anode of evacuated tube 111 iS connected, thfough Svvitch 259, vvithSvvitch contact 33 t() Which Hne 34 iS a1so connected. The cathode oftube 111 is connected to conductof of line 36, Which is connected topositive line 36 and to bfuSh 120 in contact With slip fing 42,. S1ipfing8 43, and 44,, also have SiInilaf bfusheS connected to line 36 aSindicated. The gfid of tube 111 is noffnally biaSod negatively to cUto1by battefy 121 the positive tef- 111iI1al of Which is connected to thecathode of thyfatfon 109, and fo an end of fesistof 110 the othef end ofvvhich is connected fo negative 1ine 96.

1elay coi1 31 iS connected iff SefieS vith Solenoid 5 and felay afm 31is oonnected to the anode of tube 31. Relay contact 31 iS connectedWith1he cathode of tube 31 and so, vVhef1 Solenoid 5 iS enefgized, fofpef foffI1ing divisio1 of snbtfaction, felay coil 31, Wi11 boSin]UltaneoUSly enefgized to bfing affn 31 against contact 31 to Shoftcifcuit tube 31. 11esistof 31 nlay bo included to Hn1it the cuffent.ThiS insufes that the flegative line of the coonting cifcoits 1vill beconductive fof diviSion of Subffaction. This felay co111d of cof1fso beclosed nlanually.

Slip fings 122, 123, and 124 afe faStenec1toohaft 37 to fotate Kith it.These fingS have an insulating poftion of p1astio of othef n1afefia1 anda Inetal poffion. The ffleta1 of conducting poftionS of the fings afe incontact with tho fespective associated bfuSh paifs 125, 126, and 127Whno the sweeping bfUSheS Undef key Segments 42, 43, ono 44 afe inpoSition to stfike any of the contactS of thesef1xed Segnlents. vvhenthe bfusheS 128, 129, and afo out of opefating position the bfusheS 125,126, afld 127 afe in contact With ifls11lating poftionS of theifaSSociated slip fingS. Tho detailS afe seen Inofe clear1y in thoenlafged vieW of Fignfe 40 and in Figufes 4o, 4d and 48. The bfuShes128, 129, and 130 afe staggefed so that tho caffy ovefs vvill opefafe insequence.

one bfuSh of each of the bfuSh paifS 125 and 126 iS connected topoSitive life 36, Which iS connected With tho cathodo of evacuated tubo111. Lino 36 is alSo con nected vvith bfush 120. Likevvise, one bfush ofbfush paif 127 iS connecfed to 1ine 36 thfough conductofS 131 and 36.BfuSh 132, in contact With slip fing 43., iS also connected to line 36thfough oonductofS 131 and 36. Bfush 133, in contact vvith slip fing44,,, is connected to lineS 36 and 36 Teffnina1 134 of key segfnent 42iS e1ectfica11y connected With the laSt of fenth contact 201 againStvVhich bff1Sh 128 Sweeps in conntef clockWise difection as vieWed ffomthe fight. Detai1S of the 1f11ltip1icand of divisof keyS and contactSafe Shown in FigufeS 4o and 5 Which Wil1 be desc1-ibed latef. The tenthcontact in both units 42 and 43 afe Sin1ilaf to contact 201 shoWn inFigufe 4z. Teffnina1 135 is connected t() the ninth contact 202 and tocontact 136 againSt vhich felay annatufe 137 iS puned when fe1ayvvinding 138 is enefgized. Afn1atufe 13713 nofnlany touching contact 139connected With tefn1inal 134.

1elay vvinding 138 connects the cathode of thyfatfon 140 and negafiveline 96. A bias battefy and foSistof 141, in sefieS, connect the gfid ofthyfatfon 140 vvith lino 96, the battefy biaSing the thyfatfonnegative1y fo pfovent conduction nofn1ally. Tho anode of this thyfatfoffis connecfed to the othof bfuSh 125. 14ffnatufe 137 13 oon11ected tofolay contact 49 byn1eaS of condncfof 142. sinTi1afly, felay contact 50iS connected to felay afna t11fe 143 by ffleans of condoctof 144 andfelay contact 51 iS co11ected to felay afn1atufe 145 by nfeanS ofconduotof 146. The anode of thyfaffon 147 is connected vvith thefen1aining bfuSh 126 and felay ooi1 148 iS connected botWee1 the cathodeof thyfatfon 147 and negative line 96, thfough conductof 149. ReSistof150 iS connected to lif1e 149 and to the positive teffninal of a biaSbattefy having itS negative teffnina1 connected vVith tho gfid ofthyfatfon 147. Relay contact 151 is connected With tefn1inal 152 vvhichis connected v/ith the 9 of next to last oontact ofn1ultiplicand-divisof Segnlent 43. Ie1ay con tact 153 iS connected vvithtefminal 154 Which is con nected Nvith the last of tenth confact of unit43.

Tl1yfatfon 155 iS Sifnilaf to thyfatfonS 140 and 147 and oaS its anodeconnected to one of the bfushes 127 the othef of vvhich is connectedwith poSitive line 36 by con ductof 131. 1eSistof 156 is connected t()the positive teffninal of a biaS battefy the negative toffflinal ofvvhiCh iS connected to the gfid of thyfatfon 155. Relay coi1 157 iSconnected between the cathode of tube 155 and Hne 149 and so to negativeHne 96. 1\e1ay contact 153 iS connected With the teffnina1 159 connectedvvith the ninth contact of fnultiplicand-diviSof unit 44. Relay co11-tact 160 is conflected With teffflinal 161 vVhich is con f1ected vviththe1aSt of tenth contact 201 of Unit 44. Thy fatfonS 140, 147, and 155afo nofn1any biaSed negatively to be nonconducting. Likevvise, felayafITlatl1feS 137, 143, and 145 afe 1ofInally held by Spfings in contactwith contacts 139, 153, and 160, fespectively.

Fof division, Svvitch 11 is bfonght into connection vith sWitch contact33 and sWitch 259 is o1osed. Then poS- tive line 12 iS connected Withthe anode of thyfatfon 109 Which doeS not fife until ffletal inseft 41f111Sh With the pefiphofa1 sufface of disc 41, is fotated in thedifection of the affow nnti1 it bfidges bfushes 115 and 107. At thattifne cuffent ffom battefy 116 paSSeS thfough fesistof 114 in 3,difeofion to cause a poSitive net bfas to be ap pHed to the gfid oftllbe 109 so that thiS thyfatfon is fifed 11eSistof 100,, n1ay beinclIlded fof ba]anCe. Conductive inSeft 41 iS so placed that tube 109iS fifed juSt befofe any of the bfuSheS 128, 129, of 130 StaIfSSvveeping Undef divisof contacts of l1nitS 42, 43, of 44 When thyfatfon109 isfifed, tho g1id of tube 111 is fIlade positive due to c11ffent11()vv thfough fesistof 110 and so the positive bfuSheS 120, 132, afld133 afe fflade effective fof pfodUc ing p111ses in the nuIneralthyfatfon SySten1 only at a position of positionS of bfuSheS 128, 129and 130 coffeSpond -ing to pfopef stafting pointS and not aftef thebfusheS 11ave paSSed the fSt diviSof confact as fflay othefvviSc havebeen the caSe BiaS battefy 134 is connected With the gfid of thyfa tfon108 and to tfansfoffnef Winding 135,, Which is con nected to negativeHne 96. Nofmany, battefy 134, bfases the gfid SU01ciently negatively topfevent conduction of the thyfatfon, When, ho Vevef, thyfatfon 108 is6fed, thyfatfon 109 iS extinguiShed and bias battefy 121 quick ly biaSeStI1be 111 negatively to Stop ffow of coffent ffofn Hne 12 thfoUgh thistnbe- Aftef thyfaffon 109 iS fed aS a feSult of contact 41 bfidgfngbfuSheS 115 and 107, thiS ASSuming that bfush afnTs of blades 77 and 78afe fouching contactS 79, fof diviSion, the

bfushos 130, 129, and 128 vvill continue to put pU1ses into fesiStofs 20and 20` until a 9 Shows up in n11fnefal Coll1fnn F, the nI1fnefalSincfeasing in t11e difection Shoxvn in Figufo 1, i.e. the division 9,safe oquivalent to n1111ti p1ication 0,S.

vVhen the 79 thyfatfon iS fired fof fow F then a sud den fl1sh ofonffent in pfiInafy Winding 82 in sefies Wit11the 9 tllbe of fow FindI1ces a volfage pL11Se in aSSo ciated Secondafy vvinding 02 of thetfanSfofIT1ef and thiS 13111Se will undef thoSe cifcuInStanceS beapplied acfoss fesiStof 99 in a difectfo1f to biaS the gfid of t11be 57posi tivoly t11ofeby fifing this thyfatfon, SWifch 101 having boenc1OSed. vvhen thiS happens cuffent ffofn positive line 12,,, paSSesthfough feSistof 58, thfough conductof 59 and feSiStof 56 and on thfoughthyfatfon 57 to negative line 96. The cuffenf 11ovv SetS up a potentia1diffefence acfoSS the endS of fesistof 58 b11t cuffent doeS not 0owthfough felay coil 52 until contact 39, of diSc 39 iS bfought afound sothat it bfidges bfushes 54. /f that tinTe cuffent ffofn fesistof 58 ovvSthough felay coi1S 52 and 263 and felay affnS 45, 46, and 47 fe SnapPed()vef agafnSt feSpectivo contactS 49, 50, and 51 in a ffaction of aSecond. Con tact 39, is placed in diSc 39 in Such a posifion that itcloses the cifo11it to the fe1ay coi1 j11st aftef the bfuShes 128, 129,and have pasSed beneath the last of tenth contacts of key unitS 42, 43,and 44.

vVhen felay afn1S 45, 46, and 47 afe Snapped ovef as desofibed, thefespective SWitch bladeS 74, 75, and 76 v/i11 be electfica1]y connectedvvith the laSt contact tefn1inalS 134, 154, and 161, feSpectively, ofkey unitS 42, 43, and 44, thfough fespective felay afmS 137, 143, andand aSSociafed contacts 139, 153, and 160. The felay afms 45, 46, 47 afepuned ovef as desofibed befofe bfusheS 128, 129, and 130 fotate thfougha Suf11cient angle to wipe undef the key 11I1it contacts again. v7henthese bfushoS again toUch the key unit contacts, felay 48 haseffectively sWitched the connecHons of bladeS 74, 75, afld 76 ffom thebeginning of zefo cootacts to the othef end of tenth contacts 201 of thekey unitS Which contacts are connected With fespective teffninaIS 134,154, and 161. Thefefofe theSe bfuShes Wi11 then pulSe the cifcuitsincIuding bladeS 74, 75, and 76 a nun1bef of tifI1es coffeSponding to 10ff1in11S the key nnInbef depfeSSed fathef than the nuInbef depfeSSed.Fof in Stance, if the 7 key of unit 42 is depfesSed then tho cifcuitinc1uding blade 74 w01 be pulSed 3 times. If the 5 key of uI1it 43 iSdepfeSSed, then tho cifcnit including blade 75 WiH be pulsed 5 tiffles,and if the "2 key of unit 44 is depfeSSed then the cifcuit includingSWitch blade 76 Wi11 be pulSe(1 of eflefgized 8 tinleS.

Affef the bfuShes bave paSSod nndef the laSt of tenth contactS of unitS42, 43, and 44, contact 40 in diSo 40 bfidgeS bfusheS 55 and closos thecifcuit ffom bat tefy of othof cnffent so11fce 61, including felayfeleaSo coil 63, felay coil 63 pfifflafy winding 60 of tfanS- fofInef TInagnet coi1 62, and tfanSfofnef pfiInafy vVind ing 162 Which iSaSSociated vvith secondafy Winding 163 connected in sefies.WithtfanSfofn1ef pfifnafy Vvinding 164 vvflich iS associated vvith secondafyWinding 135, con necting the poSitive pole of biaS battefy 134 andnegativo line 96 vVhen contact 40,, iS SvVept undef bfuSheS 55, thuScIoS ing the cifcuit ino1uding battefy 61, felay latch 53 fs quioklyUHed away to feleaSe afm 45 so that the fe1ay Spfing quickly puHS affns45, 46, and 47 again into con tact with felay contacts 49 50 and 51,,,fespectively. 14Lt the san1e tine the Sndden cllffent in pfin1afyWinding 60 induces a p111Se of potentia1 in Secondafy Winding 106 vVhichInofflentafily biases the gfid of thyfatfon 102 poSitively So that thiSthyfaffon iS 6fed, thefeby extinguiShing thyfatfon 57 thfough the agencyof chafged condenSef 104. siInultaneouSly, the cuffent pulSe intfansfoffnef vvinding 162 inducoS a ctlffent pulSe in Secondafy Winding163 which oal1SeS a p111se of cuffent in tfanSfofmef )fi n1afy Winding164. This cuffent pulSe induceS a poten tial pn1Se in secondafy Winding135,, Which, ten1pofafi1y biaSes the gfid of thyfatfon 108 positivelyand so fifeS thiS tube, Which canses thyfatfon 109 to be eXtinguiShed,due to chafged condenSef 119,

vVhen felay coil 63 iS tfavefSed by cuffent, felay coiI 63 in sefiesvvith it is SifnultaneouSly nlagnetized and puHs folay afm 264 ovefagainSt a Stop So that the cifcuit including bfuSheS 55, battefy 61,coils 63 and 63 and the othef coils in Sefies, iS opened bUt Since felaycontact 265 is an elongated vviping contact, the enef gizafion of coilS63 and 62 Wi11 be Inaintained SUfflciently 1o5g fof 1tch 53 ano am 54 fobo fnovod thfongh opef5.tive diStances. 1e1ay afn1 254 haS no attachedSpring So that it Temains agnst the Stop as shown, afte1' beingnlagnefically pUned ovef by onefgized coi1 58 and it enTainS in contactvvith Wiping eleInent 255 after being n1agnetically poned thefeagainStby relay coil 253 vvhen enefgized as a TeSL11t of contact 39 bTidgingbfuSheS 54 aftof curfent f1ov in TeSisfor 58 is eSfablished. 11elay arn1254 then feTnains touching contact 255 11Iltil felay coi1 53 is againenergized fo puH the afII1 254 ovef again as descfibed. Coi1 253, beingin sefies with coi1 52, is onofg1zed SiInl11taneously wit11thatcoil.This conStfuction pTevents coilS 50, 52, 1 2, and 53 ffon1 being fepeatedly onefgiZed due to fepeated ITloven1ents of con fact 40,, paStbfuSheS 55. Paw1 55 iS thefefore 1eleaSed only aftef coil 52 iSenergized and aftef contact 40,, subsequent1y bTidges the bTuSheS 55.

Magnet coi1 52 is enefgized sin1111taneously With coi1 53 and quicklyattractS afm 54 So that paW1 71 iS yieldingly pfesSed againSt the edgeof notched diSc 57 and paWl 55 is Totated abont pivot 59 oIlt of a notch55. vVhen this happens, SpTing 240 vvhich vvas put undef tenSion byaTnatUfe 155 of So1enoid 155 being dravvn into the so1enoid aS a TeSultof the eI1efgization theTeof vVhen svvitch 11 is closed againSt contact33, p1111s on cofd 157 and rotates diSc 57 half a notch SpacingclockWise unti1 paW1 71 fa11S into a notch. vVhen the enefgization ofcoi1 52 ceaSes a InoInent later Spfing 70 quickly pUnS pavv1 55 backagainst diSc 57 and it fallS i11to fhe neXt adjacent notch, thefebystopping the disc one notch fur thef in clockWiSe difection of inposition so that Switch b1adeS 74, 75, 75 have all n1oved one contact inclock- Wise difection so that Telay arnlatuTes 45, 45, and 47 Wnl beelectfica11y aSsociated With. say, fho thyfatTons of fows D, C, and BinStead of With rowS E, D, and CaS be fofo.

Tho.situation as descfibed is that bfushes 128, 129, and 130 have itlStpaSSed undef theif 1ast of tenth contacts, and contact 40 has closed acifcuit vvhich haS cauSed deenofgization of coil 52 and teoporafyenergization of ooi1 53 theTeby feleasing felay afnos, 45, 45, and 47,and tho c1osed Cifcuit haS a1so eXtinguiShed thyfatroh 57 so tha1 cof152 Will not be energiZed When contacf 39 neXt bfidgeS bfuSheS 54 and,likevviSe, thyfatron 109 iS extinguiShed, thereby cauSing tube 111 tobecome *non conductive in effect llntil contact 41 fotateS nearly half afevolution and bfidges and bruSheS 115 and 107 again, thefeby fifingthyfatTon 109 and oa11Sing tube 111 to apply voltage to bfuShes 120,132, and 133 at the pfopef fif1o. 1t iS I1ot osSentia1 that tube 111Sha11 cut off ounent from these bfnshes nntil the 1ast neceSSafy SWeepof bfuShes 128, 129, and 130 fof the pafticulaT division involved, isfrlade. TIlbe 111 sho111d be biaSed to cI1t off at that tin1e hovveverto prevont bfuShes 128, 129, and 130 ffom continuing to feed pu1SeS intothe nuIneTa1 1hyfatronS 71, B, C otc.

Counting unit 158 comprises a plurality of rows of thyfatrons andlafnps, 11, 1, 1, 1, each fow of thyfaffons being connected in acounting circuit siInilaT to that in Which thyfatfonS 9 afe connected asshown in Figofe 1. Each thyratron may likewise be conoected in se TiesWith a lamp siIni1ar to lamps 8. These 1ampS, When 1ighted, i1111nTinateone of the nun1eTal vvindows in each fow 11, 1, 1, 1 Which has beenpu1Sed by applying en ofgy 'to TeSiStofS 20 20 20 20 in Sequence, of tosoIne of these resistofs, depending upon the nuInber of digitS in thedividend. one teTIninal of each of fe- 1StoTS 20 20 20 and 20 iSconnected to Telay affnatufo 174 vh1ch iS puned againSf contact 174vvhen felay coi1 175 iS energized. Contact 174 is connected vvith 1)ruSh170 and coil 175 iS connected in serieS vvith Te sistof 175 andthyTatron 177 betWeen positive lino 12,, ond negative line 95. Brush 171is connected to 1ine 95, These bfuShes afe suitably pTeSSed against theedge ofdisc 172 Which iS faStoned to the shaft 37 of motof 10 88.-11eta1 bar of contact 173 iS iiSeffed ff1 fho fofo 1ating disc 172 0UShWith the peTipheTal surface thefeof.

The negative pole of biaS battefy 177,, fs connected fo fhe grid of tube177 and the positive pole of this battery is connected to a tenninal oftranSfofnlef secondary 178 the other end of Which is connected to line95. TfansfofIIler pfiInafy 179 aSSociated With Secondary 178 is connected in SeTieS With tfanSfofIneT Secondafy 180 vvhich is associatedvith pTiInafy vvinding 181 connected betWeen 1ine 34 and fesiStof 118connected to the anode of thyra tTon 109. The biaS battefy 177,, iSconnected to the gfid of thyfatron 177 to bias it negatively to cuto1fnormany,

The anode of thyfatfon 182 iS connected to poSitive line 12,, throughfeSistof 183 aI1d condenSer 184 iS connected betvveen the anodeS ofthyfatfons 177 and 182. The cath ode of thyfatfon 182 iS connected tonegative line 95 and the negative pole of bias battery 185 is connectedto tho gfid of thyratfon 182. The poSitive pole of this battofy isconnected to one tefIf1inal of tfansforInef SecondaTy Winding 185 theother end of which iS connected to nega tive line 95 TfansfofInerpTiInafy vvinding 187 is connected in Series vith tfanSfofnlef secondaryWinding 188 Which is aSSociated vvith pfinlaTy Winding 189 connected inSerieS With Tesistof 117 betWeen conductor 34 and the' anode ofthyfatfon 108.

Positive 1ine 12 iS 11eXibly connected to feSilieI1t nletal sWitch afm190 extending fTon1 inSulating disc 57 in Tadial direction. This SWitchaTIn is adapfe(1to be brought into contact wh meta1 b11ttonS 191, 192,193 and 194, conSecutively aS diSo 57 is Inoved ffon1 its extrenle leftposition to itS eXtreme right poSition shown. when arm 190 is iI1contact With button 191 SWitch aTIT1S 74, 75, and 75 aTe touchingTespective butfons of contactS 29, 28, and 27. vVhen arln 190 toucheScontact 192, arIns 74,. 75, aId 75 toI1ch Tespective contactS 28, 27,and 25, vheo arn1 190 iS in contact With button 193, arIns 74, 75, and-75 touch Tespective contacts 27, 25, and 25, and When arn1 190 touchescontact 194 aS Shown, afIns 74, 75, and 75 tonch Tespective contacts 25,25, and 24 aS illustfatedv 1 he 1avv1 or catch 55 ositionS the diSc andarII1s aS de- Scribed by fa11ing into the S11cceSSive notcheS 55 aSmagnet 52 feleaSes the catch SucceSSively. The contacts of bUttons areof couTSe sI1itably Snppofted on inSUlating plastic of othef inSulatingmatefiaL ContactS 191, 192, 193 and 194 are connected, reSpectively,With the positive potential endS of feSistofs 20 20 20 and 20 by IIleansof conductorS 195, 195, 197, and 198. ResistorS 20 to 20 Serve siInilarfunctions as resiStofS 20 20 20 etc. for the aSSociated fovs ofthyfatrons. vhen cuffent ffon1 positive line 12 is sent thfough Tesistor20 a pUlse is put into the multiple fhyfa tfon counting circuit11 and aSuccesSive thyfatTon iS fifed each tiIT1e a 1)111Se of curfent travefSeSfesiSfof 20 T11e counting cifcl1itS for the rows 11, 1, 1, 1, except fo1cafryover, are connected i1 the san1e Inannef as tho counting circuitfoT Tow A of FigUTe 1 bI1t in rows 11, 1, 1, 1, thefe are 11 thyfatfonseach inStead of ten thyfatfons as en1ployed in each of the rOWS A to F.The nu IIleTalS of llnit 158 indicate the seqUence of firing of thothyfatfons but the fifst thyratron unitS in each row aro not nuInbefed.The Second thyratfon 1nit of aSSociated vvindovv of each Tovv iSnun1befed 0 and thiTd x indowS aTe nunlbered 1 and so on Up to theeleventh vVindowS Which aTe nun1beTed 9. ThiS iS done since the Unit 158iS pulsed once fof eacf1 fevolution of Shaft 37, after tho in1tiatingthyTatTon 177 is 5Ted and the pulSing per fevolution continues untilthyfatron 182 is fired. Tho latter thyratTon is 5red as a feSult of a 9showing to the left of SWitch arn1 74 bnt thiS represents one fevolutiontoo oTany. Thefefofe, if the nufnefal indication foI each fov ofdividend unit 158 iS one leSS than the nun1bor of thyfatfons f1fed forthat fov, fhen the cofrect nun1efals of the dividend WH1 be shown in theWindows.

The conSffuction of Tnultiplicand-divisof key unitS 42, 43. and 44 isShoWn in Figufes 45 and 5. Each of theso bfok the cifcuft vvhen the nextinSI11ation e1eII1e1t 224 is passed ovef and the cifcUit WiH siInilaflybe made and bfoken once fof each succeeding key including the key WhichiS depfeSSed. Since the depfessed key bfeakS the cifcuit leading ffombfUSh 130 back thfongh the sefies connected elen1entS as descfibed, thebfuSh vvi11 not be 111 cifcnit beyond of fofWafd of the key depfeSSed.If desifed, eleInents 207 n1ay be of fesilient constfuction of n1ay besWive1-n1ounted on the key Sten1S to insufe that both n1etal contactS202 on eithef side Wi11 be touched. t is pfefefable that the zefo keySteIn 229 bo of Bakelite of othef inS111ating Iflatefial, of that contact 228 be inSUlated ffom the stem if it is of meta1.

When any key is depfeSsed itS cam 209 quickly Stfikes a can 210 and1)L1Shes cllfved stfip 211 a shoft distance in contef clockWisedifection. vVhen this happenS any key a1feady depfessed iS feleased dueto itS catch of oafn 210 being caffied aWay ffom itS cam of catch 209and so the key Spfing 227 quickly fetufns the feleaSed key to itS nofnlal position With its meta1 element 207 bfidging the Sepafated contacts202 on eithef Side. Shoftly thefeaftef the oppef Sufface of the cam 209of the depfeSSed key hooks undef the asSociated cam element 210 asspfing 214 quickly fetufns elefflent 211 to its noffnal position WithStop 210 against beafing 213. Thefefofe the key is held in depfessedpoSition With its elenlent 207 ont of contact With associated elefnentS202. when any othef key is depfessed, the key alfeady depfessed isSiInilafly fe1eased, due in paft to the n1oInentum of elenlent 211caffying the oatches of cafnS 210 S1ight1y beyond the aSSociated can1s209.

Solenoids 100 and 234 afe Suitably attached to the fflachine ofcofnputef as afe othef components ShoWn dia gfafnn1atically. onefeffnina1 of each of theSo solenoids iS connected fo conductof 242vvhich is connected to nega tive lifle 90. The othef tefn1inal ofsolenoid 100 iS con nected to felay contacts 245 and the othef tefn1inalof solenoid 234 iS connected to felay contact 243. Plungef 235 ofsolenoid 234 is attached to ffeXible cable 230 Which is attached to ane11d of tensioI1 spfing 237 fhe othef end of vvhich iS faStened to0exible cablo of belt 107 passing afound pulley 238 vv11ich is fotatableafound 0xed shaft 08. PuHey 238 is integfal With of attached to diSc 07.Belt 107 is attached to pnHey 238 by meanS of scfeW 239 and iS alSofaStened to an end of tenSion spfing 240 the othef end of Which isattached to an end of 0ex ible cable 241. The feInaining end of thiscable is fastened fo pIungef 105 of solenoid 100. Vhen Solenoid 100 iSenefgized itS plnngef 105 is puHed into the solenoid and spfing 240 isStfetched su01ciently to inSufe that diSc 07 and sWitch affns 74, 75,and 70 Wil1 tfavel ffoff1 theif eX- tfen1e left of stafting position fotheif extfen1e fight posi t ioI1 shovvn, When oatch of pavv1 05 iSfeleaSed a Su0icient nun1bef of fin1es. Sifflilafly, When solenoid 234is enef gized, and Solenoid 100 is deef1efgiZed, plungef 235 is p0Hedinto solenoid 234 and spfing 237 is Stfetched su0i cient1y to inSufethat diSc 07 and SWitch afms 74, 75, and 70 Wi11 be fotated ffom theifstafting poSition Shovvn to fhoif extTefne left poSition Wifh theSeSvvitch afn1S in con tact vith feSpective contacfS 29, 28, and 27, vvhenpawl 05 is actuated a Su0icienf numbef of times.

vVhen switch blade 11 is thfovvn to contact 33 fof diviSion, Solenoid100 iS enefgized and plungef 105 is dfaWn into the Solenoid as shoWn.tJndef this condition spfing 240 is stfetched and diSc 07 is ufged inc1ockWise difeotion. vvhen sWitch blade 11 iS thfown to contact 35 foffn111tiplication the solenoid 100 iS deenefgized and solenoid 234 iSenefgized thefeby cauSing plungef 235 to be puned into the solenoid andStfetching Spfing 237 to ufge diSc 07 and aftached svvitch afITs incountof clockWise difection. 1t Will be obSefved thaf, Since onetefn1inal of solenoid 5 is connected to line 10 (of to negative line 90)and since the othef tefInina1 iS connected to tefffina1 fhen solenoid 5vvi11 alSo be enefgized vvhen svvitch blade 11 is touching contact 33.The nlachine is set fof fnI11ti1)1icfitionby thfowiog SWitch 11 tooonfaof 35 ood iS Sef fof diviSion by thfowing sWitch 11 to contact 33and closing sWitch 259 and SWitch 101,

BfuSheS 123, 129, and 130 afe staggefed of phaSed so that bfuSh 130vvi11 fifst Stfike contact 202 then bfus11 129 Win stfike itS fifStSiInilaf InultipHcand contact, and then bfuSh 128 Win Stfike itSequiva1entfifSt contact. Tho bfushes may bo affanged so that any bfuShWhich haS SvvepfacfoSS a contact Wil1 be touching an insulating elenlent 224 WheI1 the 11ext bfush stfikeS a contact. vvhilo thfee bruShesafe shovvn the phaSing fflay be affanged fof any I111ff1bef of bfusheSSo that they touch theif felated contactS in succeSSion, fof the vafiouScoluIT1nS, stafting vvith the fifst col1IT1n at the fight. By fneanS ofthis soquential of phaSed affangen1ent of f1fing the thyfatfonS, thecaffyovefS can opefate Without infeffefence. Suitable sepafating oftiffle delay of Stofage cifcuitS could bo uSed.

The connected tefn1inalS of SolenoidS 234 and 100 afo connected tonegative line by conductof 242. T'ho othef tefn1ina1 of Solenoid 234 isconnected to felay con tacts 243 and 244 Which afe connected togethef.The felay has thfee fe1ay afn1S of affIlatlIfes 240, 247, and 243oonnected, feSpectively, to SvVitch contact 35, SWitch contact 33, andto positive line 12 1)ouble felay con tact 245 is noffnally touchingafn1 247 and affI1 240 iS nofn1any nfged against contact 244. Contact245 is con nected With tho fe111aining tefIT1iIlal of solenoid andcontact 249 iS connected With one tefIninal of fnagnet coi1 250 Which isadapted to pun paW1 05 out of a notch 00 vhen onefgiZed. The otheftefII1inal of solenoid 250 is connected to negative line 90. Relay coil251 is ada ted fo pnn an thfee felay afmS 240, 247, and 248 towafd itvv11en the coi1 iS enefgized, Which iS accoInpHShed by c1oS ing cleafingswitch 252 the blade of vvhich iS connected With )ositive line 12 andthe aSSociated contact is con necfed With a tefn1inal of coil 251 vvhichcoil is alSo oon nected vvith negative line 90. It Will be seen thatcoi1 251 vvill bo SUpplied vith cuffent vvhen Svitch 252 is cloSed andafII1 248 vvill be puned ovef against contact 249 thefeby causingcuffent ffom positive line 12 to paSs thfoI1gh Inagnef coi1 250. Theothef felay afInS vi1l bo sifI1111taneouSly n1oved clockWiSe about theifpivotS So that afIn 240 iS agaiI1St contact 245 and affn 247 iS touchingcontact 243. vvhen thiS happenS, afn1 240 vVi11 be co11 nected Withsolenoid 100 inStead of being connected With solenoid 234 aS befofe, andafm 247 Will be connected With solenoid 234 instead of being connectedvvith Solenoid 100 as befofe. Since SWitch contact 33 is connected vvithafn1 247 and since contact 35 is connected vvith afn1 240, contact 33 isnofmally connected with Solenoid 100 and contact 35 is noffflaHyconnected with solenoid 234.

vv11ef1, hoWevef, coi1 251 is enefgized, contact 33 is connected vithSolenoid 234 and confact 35 is connected With Solenoid 100. The feaSonfof this fevefSal of Connections is that aftef disc 07 and afmS 74, 75,and 70 afe fotated to theif 0nal position, aftef a calcUlation, theyn1USt bo fetufned to theif sfafting poSitionS fof anothef SiInilafcalcI1Iation. The position of SWitch blade 11 with fespect to contact 33of contact 35 detefII1ines Whethef S )fing 240 of Spfing 237 Shallnoffnally be stfetched by one of tho Solenoids- Then, the fenlpofafycloSing of cleafing SWitch 252 Will canSe fevefSa1 of Solenoidenefgization, fegafd lesS of Whethef contact 33 of contaot 35 iSconnected vith blade 11. Thefefofe, Upon closing SWitch 252, spfing 237Will bo Stfetched if Spfing 240 was alfeady stfetched, and Spfing 240vin be Stfetched if Spfing 237 happened to be alfeady Stfetched. In anycaSe then, Whethef tho 0na1 position of diso 07 is at the extfen1e fightof at cx tfen1e leff, if is fetufned to stafting poSition vvhen cleaf,ing SWitch 252 is tefnpofafily closed. Tis sWitch may bo a button typeof of any deSifed constfuction,

1fIn 253, vith fight angle eaf, is infegTa1 vvith pav1 71 and Inay befotated abo11t pivot 72. The eaf nofnla1- 70 1y pfoiectS beyond theboundafy of paW1 05 and il odaptod to Stfike the ollter Snffaco of theoofo of oleotfonfagnet 250 When thiS coil is enefgized, vvhen then1agnet cofe is struc k, arn1 253 iS rotated clockWiSe about pivot 72and pawlS 65 and 71 aTe accordingly swung aWay fron1 notched disc 67theTeby TeleaSing this diSc so that it can be Teturned to staTtingposition by eitheT SpTing 237 of Spring 240. vVhen svvitch 252 iS openedit iS preferable that aTIn 248 Inove avvay ffoTn contact 240 befofeaTII1S 246 and 247 n1ove oI1t of to11oh vvith Tespec tive contacts 245and 243. T,his Inay be accoInpHShed by Inaldng the contactS of TesilientconStTuction and 1in1 iting the n1oveInent of contact 240; of vvipingcontacts may be used for tiIning puTposes; o1 arm 248 Inay not berigid1y connected vvith the other Telay aTII1S and Inay be pTovided witha Stronge1 retUTn spring than the otheTS. Thefefore pav1 65 vvill bereleaSed to engage a notch 66 befofe Solenoid 166 of Solenoid 234 iSdeenergiZed.

In ordel to pefforIn a division, asSun1e that a suitable Svitch iScloSed to enefgize the cathodeS of an the electronic tUbes, WhichcathodeS Inay be heated by a1tefnat ing or direct cnrrent. Then n1otof38 iS connected to a suitable Source of current so that bfusheS 128, 12,and 130 are fotated Undef the II111ltip1icanddiviSof key con tacts fron1to 9, Tepeatedly, Svvitch 101 iS cloSed and switch 11 is moved intocontact with SWitch elen1ent 33, thefeby causing solenoid 166 to puHcord 241 to stTetch spring 2404 These tWo SWitcheS may be 1inked tooperate together. Then clearing SWi1ch 252 is cloSed fo1 a ShoTtintervaL So1enoid 166 iS deeneTgized and Solenoid 234 is energiZed topuH diSc 67 and attached SW1tch aTnls counterclockvvise until lug 262 ondiSc 67 Strikes Stop 254. When thiS happens aTn1S 74, 75 and 76 aretouching reSpective contactS 28, 27 and 26 and SWitch arI11s 77 and 78are in contact With the pair of sWitch e1ementS 70.

SWitch 252 iS opened and solenoi(1 166 iS again eneT gized, StretchingSpl-ing 240 but diso 67 is held by paW1 65 in a osition vvith Svvitcharn1 190 touching contact 102. LikewiSe arIns 77 and 78 are thentouching Tespec tive contacts 70 as descfibed so that tranSfor1er vvinding 82 is connected with the tWo teTII1inals of tesiStoT 00, and SWitcharlns 74, 75, and 76 are then touching re- Spective contactS 23, 27, and26. The closing of c1ear ing SWitch 252 also cauSes the O thyfatTons oftubeS 9 (FigUre 1) of each fow to be 6red and also cauSeS the sta1tingthyratfonS 255 of unit 168 to be 111ed, by IneanS t() be deScribed laterin connection With FignTe 9.

The c1osing of SVvitch 11 also causeS cufTent to paSS thTough solenoid 5So that its p1Ungef 6 puns nnmefal Sheet 3 toward the solenoid unti1 theplunger iS Stopped. The 1ine line nIlITleralS of Figure 2, fof diviSion,are then in fegiSter With the windows a indicated in Figufe 1 but onlythe i11u1inated nI1TIlefals vvin be eaSily visible aS pTevionslydescribed. Due to the connections of the th ratronS, they vvi11 be 6redthen in the ordeT 9, 8, 7, 6, 5, 4, 3, 2, l 0, aSsnming that a11 the 0thyratronS are initiany fiTed. Therefore, for each current of voltagepulse pasSed throI1gh a reSistof 20 20 or the like, one digit vH besubtracted ffoII1 the aSSociated indication in a nunlera1 vvindow, The 0thyratTons for division aT the sanTe aS the 9 thyratronS forn1ultip1ication. Therefore if it iS deSired to 1ife all the 0 thyfatronsfo1 dviSion, the cleafing circI1it should have a SepaTate In11- tip1cpole re1ay o eaed in like manner to that deScribed in connection withFignTe 9 bI1t connected to 1iTe the 0 division thyratfonS. TheSethvyratrons can of course be 6ted by pTeSSing the pfopeT buttons 256 anda coIn' nlon switch or bar, OpeTated by the division cleaTing Inoans,can be n1ade to f1Te these tllbeS.

NeXt, the proper buttons 256 are preSSed to 6re the desifed 1hyfatTonscorreSponding to the nllIflber to be divided. Buttons 2-56 OpeTateSvvitcheS 257 connected between the thyratfon gTids and the cathodeS ofconnected nogative lines. ()nly a few of the SWitcheS are Shown 11as aSin111afly connected Svvifch Wh1ch can be n1on1en taIily closed bypreSSing a button 256 to connect the as- Sociated thyTatron gfid to thecathode to 11fe that thyfatfon. By ineans of condenseTs 22 and SiII1ilarcondenS erS, any 0 thyratTon of any ()ther 1ifed thyfatfon iSextinguished vvhen another thyTatfon in the san1e Tovv iS fired. If, fo1instaI1ce, the number to be divided is 24780, the button 256 i11 Tow EcoTTesponding to the number 2 wiH be presSed, then the button 256 in fowD coTTeSponding to the nun1bef 4, then the button in Tow C corTeSpondingto the nllIT1be1 7, then the bnttoo in Tow B corfesponding to the nnmbeT8, and the 0 button in Tov/ A iS then presSed llnleSS the clearing cifcl1it vvill cauSe thaf thyTatron to 1ire. The pfeSSing of theSe buttonScan be done very qnickly. PTinted n11Inbers can be placed by eachbutton, corTesponding to the I111I1TbeT Which vvill be illL1Ininated ina Windovv 258 vvhen fhe associated lanlp 8 .iS eneTgized With curTent.

Now if the divisor iS to be the numbef 236 then the 2 In111ti )licandbutton in 11nit 42, the 3 button in unit 43, and the 6 bUtton in llnit44, vvi11 be depTeSSed. Then svvitch 250, Which connects tube 111 operatively into cifcuit, is oloSed and the dividing action beginS Soonafter contact 41 is fotated aTOund by diSc 41 until it bridgeS bfShes107 and 115. If the oontact iS acroSS the bTUShes at the moment ofcloSing SWitch 250 the division beginS Soon after that. (ontact 41 iS Sop1aced on diSc 41 that it bfidges these brusheS iuSt befo1`o leadingbfush 130 touches contaot 202 vvhen the contact 41 bTidges bTuShes 107and 115 battery 116 SendS cuTfent 1hrough Tesistor 114 in a direction tofife thyfaffon at once, oveTconTing the 11oTIna1 negative biaS due tobiaS battefy 113. ThyratTon 108 is previouS ly fired vhen felay coil260, vvhich iS connected in cir cuit With Inagnet coi1 250, iSI11oInentaTi1y enefgized vvhen clearing sWitch 252 iS c1osed. ThiScanses relay aTn1 261 to connect the grid of tUbe 108 to itS cathode fofa InoInent, thefeby firing the tube. Electronic tube 111 which controlScuTTent fron1 souTce 32 10 bfuSheS 120, 132, and 133 iS biasednegatively to cUtoff unt11 thyratroI1100 is 11Ted but When that occUrsthe sudden cut- Tent 11ov through fesist()1 110 pfovides a positive gridbiaS suicient to cancel enough of the negative biaS dne to batteTy 121to caUSe tube 111 to paSS apPTeciable cn1- Tent. In effect then, curTentiS SUp lied to bfuShes 120, 132, and 133 only vvhen and aftef contact 41bTidges brushes 107 and 115 The bruSh SWeepS acToss a11 the contacts 202and 202 of unit 44, and feeds a p111Se through 1elay afIn 47 fo1 eachcontact touched I1p to and inclnding the same number corfesponding tothe key depfessed. The TeInaining contactS 202 (FiguTe 4(Z) beyond thedepTessed key are oLlt of ciTcUit and do not cause pulseS. Since in theSpecific oxaInple given, the. 6 key in unit 44 Was depressed, bfuSh 130vvil1 feed Six curfent pulses thTough Telay aTTn 47. Since at thebeginning of t11e diviSion connected svvitch afn1 76 iS touching contact26 these siX pulSes i11 be applied to feSisto1 20 and so thyfatronS 6,5, 4, 3, 2 and 1 in fovv (FigUTe 1) vvill be 1ifed in succeSSion So thato111y the nuIneral 1 Wi11 ShoW in the corTespond ing window 258 of rowC. SiInila11y, since the 3 key of unit 43 is depfeSSed bTUSh 129 vvi11Svveep paSt throo contactS in ciTc11it and thfee cuTTent pu1SeS vvi11 bepassed thTough Telay aTIn 46 and connected SWitch aTIn 75 Which vvi11 bein contact vvith elen1ent 27. Therefore thfee cuTTent pl11Ses vvill beSupPlied to reSistor 20 conI1ected to contacf 27 and So thfee thyratTonSin Tow 1) vvi11 be fifed in the order 3, 2, 1, Since the 4 thyraffonv/aS a1Teady 1iTed. NeXt, bruSh 128 vvill Svveep ovel the two ContactSin cifcuit in Unit 42 and so tvvo cuffent 1)ulSes will be sent thronghTelay afIn 45 and thTough connecfed Sitch aTIn 74 vvhich is in contactvith ele nlent 28 connected to resiSto1 20 TheTefofe tvvo current pueSWi11 be sent through this resiStoI' and tWo 2,oso,833

17 hy af ons fo ToW. E Wi11 bo fcd in fho ofder 1,, 0, Since tflo. Zthyfatfon WaS alfeady 1ifed.

As oxplained befofe, the bTuShes 128, 129, aod 130 are so phased thatthey do not pfoduce overlap of inferfefonce in fifi11g the thyfatronS.othef types of Sepafafofs of tinle delayS for this purpose could be en1-ployed. The actfon so far described takes placo With ono fravofse of thoInultiplicand oonfactS by the brSheS. ()n fhe second tfavefse of thefnultiplfcand key contactS by bfush 128 the 9 thyTatTon of Tow E Wilf be5Ted, sinco the 0 thyTatfon had last been fired, and the sudden flISh ofcuffent in franSfofInef )fin1afy 83 induces a pl11so of cuffent insecondafy Winding 94 in Such difoction tflat the nornlal negative biaSof the 9 thyfatfon of fovv F iS largely overcoIne and thiS thyratfoI isthofofofe fifod. when this happens a pulSe of cuffent isdeve1oped inpfimafy Winding 82 Which induces a pulse of curfent in secondaTy Winding82 Which oufront pulSe paSseS thfough SWitch afIns 77 and 78 at thattinle TeSting on contacts 79. This cuffent pulse tfaveTSeS connectedTesistof 99 in difection to pfovide poSitive bias fof thyfatfon 57,canceHing a lafge Paft of the nega tive bias caused by battefy 95 andthuS firing this thyfaff()I1. vVhen thyfafTon 57 iS fifed, cuffent ffon1positive lino 12 passeS thfongh fesistof 58, thfo11gh fesiStor 55 andfhe thyfatfon and thfough SWitch 101 to negative line 95. The cuffenttfavefsing TesiStof 58 cfeateS a po tential diffefeI1ce acroSS the endSof thiS TeSiStof and as soon as contact 39 on disc 39 iS Totated aronndto bfidge bfUshes 54, this potential diffefence is applied to felay coil52 so that Inechanically connected Telay afIns 45, 45, and 47 afequickly n1agnetioaHy p1111ed ovef agaiI1St feSpective contacfS 49, 50,and 51. (ontact 39 is fixed to disc 39 in Such poSitiofI that relay coi152 iS onefgized Shoftly after brosh 128 haS SWept paSt the laSt contactof n1111tiplicand unit 42. vvhen an1 45 is puned ovef it iS held inplace against confact 49 by SpTing latch 53 and accordingly, afmS 45 and47 afe likeWfse held againSt fespective contactS 50 and 51.

It haS already been descfibed hovv contact 40,, bfidging bfuShes 55cauSes latch 53 fo feleaSe relay afn1 45 and Sinlultaneously caUSesthyTatTons 57 and 109 to be oxfingUiShed, aS We11 aS causing pavv1 55 tofelease diSc 57 -for one notch Tnove1ent clockvise. The diso could befeleaSed n1annany if desifed, vvhen 9,S appeaf. 1)isc 40 iS shoWndiTectly attached to shaft 37 but it of diSc 39 of diso 41 coUld begeaTed to shaft 37 to be dfiven at a diffefent felativo fate if desifed.In Son1e caSes a diffefent Tate IIlay be deSifable fo tifn1ng of phaSingpufpoSes. As pfeviously descfibed, f11o bTushes 55 afe bfidged justaffef bTush 128 has oassed by the tenth confact oonnected vvithtefIninal 134. Thofe is then a tinlo interval of approxiInately half aTevolution of shaft 37 dufing Which felay 48 may be feset and diso 57may be o1oved oIle nofoh. vVhile n1echanica1 SWitches and felays aTeshoWn electronio felays of sWitches conlpfiS- ing Suitable electfonict11bos oonld be 11Sed to pfovide very fast operation.

Since the 9 keys of depfessed keys befofe that Win alvayS bfeak thepulSing cffouit, the tenth contacts 201, foT the thfee units, Win notadd a tenth pulSe. vVhen, hoWever, Tolay afn1s 45, 45, and 47 afetouching fespective contactS 49, 50, and 51, the effective contactS vi11be those on the fofvvaTd of high side of the depreSSed key, fof anyl1nit 42, 43, of 44. 111 that event the confactS 201 connected totero1inals 134, 154, and 151 Will bo in cifcuit to pTovide pulses.

AS pointed out befofe, the number of pulSes pfoduced in oach felay aTo1Wi11 then be equal to 10 n1inuS the number of the key dopfesSed. Sincethe numefa1 thyratrons afe fifed pfogfeSsivoly in one difection only,this Inethod festofes tho f11UInfnated numerals in mWS E, D, and C backto Whefe fhey Wefe befofo the 9 thyfatfon was red iI1 mW F. This istlrue if no carr over has oocuIfod fTon1 Tow C to roW D of from roW D toro E 18 befofo, of ooufSe, latoh of aWI 55 iS folcasod to anovv diSc 57to be fotafed one notch. Under thiS condifion, aS ShoWn in Figore 8,fadiaHy directed SWitch a1mS 77, and 78, attached to diSc 57 afe incontact With elonlentS connected vvith tfanSfofoef Secondary vinding 82and Sin]f1ar afnS 77 and 78 afe in contacf With elenlenfs 81 connectedvvith ffa11SfoffIlef SecondaTy vvinding 84, and arIns 77 and 78 afe incontact With elenlenfS 81, con nected With tranSfofmef secondaTy 85 ofmw C. SWitch ar1S 77 has a. f1exible conductof connected vvith tofn1inalL Which is connected With the grid feSiStor 150 of thyfatfon 147. Ams 7878 and 78 are electricaHy conneoted to negative 1ine 10 and connectedline by^ Tneans of conductof 10 and connected ffeXible conductof 10.4Tn1 77 is connected VVith terzT1inal K Which iS connected With theglid-connected end of fesiStof 141 of thyfatron 140. AotUally, s ifchafInS 77 and 78. aro not neceSSafy to the o efation of the con1pute1 outafe shoWo. It vviH be noticed that afIn 77,. iS not con nected.

Novv, vvith afII1s 77 and 78 electrically connected vith contactS 81,and With aTTns 77 and 78 electrica11y connected vvith contactS 81 if acaffyovef occUTS ffon1 fow C to Tow D So that the numeral indicated infoW D iS reduced by one digit, then an electfical pulSe Wi11 be inducedin tranSfofITler secondaTy Windi1g 85 aS tfanS fofInef pfilnafy 87 iSSudden1y enefgized vvheI1 the 9 tube of Tow C is fired. The electricalpulse in Winding 85 is ap Hed thTongh sWitch afmS 77 and 78 fo negativofine 10 and to gTid fefI1inal L and the phasing is such hat thiS )111Sevi11 fife thyfatron 147. vVhen thiS thyra tfon is fifed coil 148 isenorgiZed afld relay afn1 143 iS quickly pulled againSt contact 151,against suitable spfing tension. vVhen thiS happens contact 50 aIld thenconnect ed relay afIn 45 are electfically connected With the I1fI1thcontact of onit 43 instead of the tenth contact Which iS conneoted WithteTIninal 154. The I1inth contact is con neoted With tefInina1 152.Thefefofe, due to fhe caffyover or Tathef, caffyundef into fow D, thennobef of coInplen1entafy festofing pulseS ofovided by unit 43 affofrelay 48 iS enefgized, is feduced by one. The thyfatfon 147 romainSfifed until the inSulating portion 123,, of disc 123 ffavelS fo bfuShes125 and accoTdi ngly bfeaks tho circuit ffoIn poSitive li11e 35 to theanode of this thyTa ffon, The tI1 be is thef1 eXtinguiShed. T11eiISulating pof tion 123 is located on diSc 123 in SIlch Iosition thatbfush 129 vvill have passed beyond the teIIth contact of unft 43 befofothe cifcuit is bfoken. Ielay affT1 143 is thon foleased to spfing backagainSt contact 153. Metal diScS 122 and 124 havo sin1ilaf insulatingportionS 122, and 124 for eXtinguiShjng fhe fespecfive thyfatfons 140and 155 aftef fhe bfnShes 128 and 130 havo paSSed beyond theif fenthconfacts.

In like n1annef, if thefe is a caffy-under ffon1 fovv D fo Tow E, as aTeSult of the 9 thyfatron in Tow 1) being fired, an electTical pu1so intfanSfofn1ef Secondafy 84 Win aSs through afms 77 aod 78 and Wi11 beappHed to tefIninal I, fifing thyfafron 140. Thfs vvill enefgize coil138 and felay afn1 137 Will be puned againSt contact So that the ninthcontact of unit 42, connected With fe1- nlina1 135, W1 bo electficallyconnected with felay afm 137 and ono leSS conlplen1entaTy TeSfofingpulSe vvin be applied to the tubeS of fovV D to caUSe theSe t11bes toShow the sanle indication they had befofe the bfuSh tfav efSe of thecontacfS vhich caused fifing of the 9 thyfa^

